Conventionally, in a weft knitting machine, a large number of knitting needles are arranged on a needle bed, and a cam apparatus for knitting a fabric is mounted on a carriage moving along the needle bed. The carriage is driven in the cam apparatus for knitting a fabric so that a knitting needle selectively moves forward into and backward from a needle bed gap, and supplies a knitting yarn to a knitting needle at the needle bed gap, thereby knitting a fabric. At least a pair of the needle beds is often disposed at front and back. In a weft knitting machine in which at least a pair of the needle beds is disposed at front and back, a fabric is basically knitted at each needle bed. By use of the front and rear needle beds, it is possible to knit textures such as a rib stitch, and also knit a pouched fabric by knitting a fabric at each of the front and rear needle beds and making both ends in a width direction of the knitted fabrics continuous. Moreover, it is also possible to carry out a transferring that a knitted loop is made to move between front and rear needle beds (Refer to Japanese Examined Patent Publication JP-B2 2946325, JP-B2 2917146, JP-B2 2995464, and JP-B2 3292836, for example).
The Japanese Examined Patent Publication JP-B2 2946325 discloses a basic idea of a method for temporarily placing a knitted loop, by use of compound needles for the knitting needles on the front and rear needle beds, from the facing needle bed onto a tongue of a slider of the compound needle retaining a knitted loop on a hook of a needle body. The Japanese Examined Patent Publication JP-B2 2917146 discloses a knitted loop forming method for split-knitting, a cam structure for the method, and the like, in which method the compound needles are used for the knitting needles on the front and rear needle beds, and a knitted loop formed through previous course is not knocked over but retained on a tongue of a slider, and transferred to the knitting needle on the facing needle bed and further, both of racking for shifting the needle bed and the transferring are applied. The Japanese Examined Patent Publication JP-B2 2995464 discloses an apparatus for the transferring and the temporal placement of a knitted loop, in which apparatus the compound needles are used on the front and rear needle beds and further, separately from the front and rear needle beds, a transfer jack is provided. The cited reference 4 discloses a structure of a weft knitting machine using the compound needles for the knitting needles on the front and rear needle beds, by which apparatus the transferring and the split-knitting can be carried out.
According to the related art disclosed in the aforementioned Japanese Examined Patent Publications JP-B2 2946325, JP-B2 2917146, JP-B2 2995464, and JP-B2 3292836, by means of the weft knitting machine using the compound needles on the front and rear needle beds, it is possible to knit not only a basic fabric, but also various fabrics by inclusion of the transferring and the like. However, the Japanese Examined Patent Publication JP-B2 2946325 does not disclose specific structures such as a cam apparatus for effectively driving the knitting needles. According to the Japanese Examined Patent Publication JP-B2 2917146, the transferring knitted loop is received by a hook of a needle body on the facing needle bed, so that the method of temporarily placing a knitted loop as disclosed in the Japanese Examined Patent Publication JP-B2 2946325 cannot be applied.
The Japanese Examined Patent Publication JP-B2 2995464 discloses a cam structure for temporarily placing a knitted loop by use of a transfer jack, and a cam structure for temporarily placing a knitted loop, having a slider holding cam provided on a slider cam on the same phase of a transferring cam and a knitting cam. However, theses cam structures are complex.
Further, in a structure having a transfer cam disposed on a knitting cam, as shown in the Japanese Examined Patent Publications JP-B2 2995464 and JP-B2 3292836, a needle is selected to one of three positions of A, H, and B, at each position of which a presser is disposed, so that change-over between driving and non-driving of needle body, slider, or the like is carried out. Such a structure requires not only a complex cam structure, but also a raising cam having right and left apexes with long distance therebetween. Accordingly, such a structure is not suitable to a knitting machine for producing knitted products having a short knitted width such as a glove and a sock, for which knitting machine frequently repeats back-and-forth motions at a high speed because the structure would cause a larger time loss.